基于花生//高粱间作模式的花生盐胁迫耐受性效应研究

【目的】研究旨在探究花生//高粱间作下花生对盐胁迫的响应,以期为逆境栽培提供新的视角。【方法】本试验以耐盐花生品种（花育25）和耐盐高粱品种（辽杂15）为试验材料,在正常（N）和0.25%盐胁迫（S）条件下设置花生单作（SP）和花生//高粱间作（IP）,分别为正常土壤条件下单作花生（N-SP）;正常土壤条件下间作花生（N-IP）;盐胁迫条件下花生单作（S-SP）和盐胁迫条件下花生间作（S-IP）,共4个处理组合。通过连续2年进行田间种植箱模拟试验,测定花生盐耐受指数（STI）、邻体效应指数（RII）、Na⁺/K⁺和根际养分等指标,研究不同种植模式下花生对盐胁迫的响应。【结果】花生//高粱间作模式下,花生RII均为负值,但在盐胁迫条件下,特别是连续种植2年后,S-IP处理组的负RII明显减弱,STI明显提高。在2019年,S-IP处理负RII较2018年降低了66.78%,相较N-IP处理降低了88.76%。2018和2019年S-IP处理STI相较S-SP处理均提高了27%左右。此外,花生//高粱间作有利于不同类型根系的发育,从而改变整体根系分布与结构并影响花生根际养分。其中N-IP处理根际土壤养分含量相较N-SP处理平均升高6.19%,S-IP处理根际土壤养分含量相较S-SP处理平均升高3.73%。盐胁迫条件下土壤钾素含量相较正常土壤条件显著增加,这可能是植物维持根际土壤Na⁺/K⁺稳态的初始防御响应,从而通过影响Na⁺、K⁺的选择性吸收与运输调控了花生体内Na⁺/K⁺稳态。相较S-SP处理,S-IP处理叶片Na⁺/K⁺降低了20.63%,叶片盐害系数（LSHC）减少了53.95%,光合潜力和光能转化效率得到明显改善,干物质积累能力和产量潜力也得到提高。其中S-IP增产潜力最为明显,相较2018年,2019年S-IP处理产量增加了17.95%。【结论】盐胁迫下连续花生//高粱间作能有效缓解花生的负相互作用,显著提高了花生盐耐受指数,并通过改善土壤养分状况和调控花生Na⁺/K⁺稳态缓解盐胁迫,维持了干物质积累能力和提高了产量潜力。

A Salt Stress Tolerance Effect Study in Peanut Based on Peanut//Sorghum Intercropping System

【Objective】The main objectives of this study were to investigate the response of peanut to salt stress under peanut//sorghum intercropping, and hope to provide new insights on develop stress cultivation. 【Method】 In this study, peanut cultivar “Huayu 25” and sorghum cultivar “Liaoza 15”, with characteristics of salt tolerance and a high yield potential, were selected as experimental materials to carry out the field planting box experiment for two consecutive years. Sole-cropped peanut (SP) and intercropped peanut (IP) experiments were then performed under normal (N) and salt stress (S) soil conditions, respectively. The experiment was comprised of four treatments: sole-cropped peanut under normal condition (N-SP), intercropped peanut under normal condition (N-IP), sole cropped peanut under salt stress condition (S-SP), and intercropped peanut under salt stress condition (S-IP). Therefore, the salt tolerance index (STI), relative interaction index (RII), Na⁺/K⁺, and rhizosphere nutrient of peanut were investigated in the present study to evaluate the response of peanut to salt stress under different planting patterns.【Result】In the peanut//sorghum intercropping system, both RII of peanut were negative. However, the negative RII was decreased significantly and the STI was increased significantly under S-IP with salt stress, especially after continuously being planted for two years. Of these, the negative RII of S-IP decreased by 66.78% in 2019 than that of in 2018, and the negative RII under S-IP decreased by 88.76% than that under N-IP. Furthermore, the STI under S-IP increased by 27.68% than that under S-SP in both 2018 and 2019. Peanut//sorghum intercropping has been found to change the overall root distribution and architecture by favoring the development of different types of roots, and also affected rhizosphere nutrients of peanut, the rhizosphere soil nutrient content of N-IP and S-IP increased by an average of 6.19% and 3.73% than N-SP and S-SP, respectively. Under salt stress, the content of soil potassium increased significantly compared with normal soil conditions, this might be the initial defensive response utilized by plants to maintain Na⁺/K⁺ homeostasis in rhizosphere soil, which regulated Na⁺/K⁺ homeostasis in peanut by influencing the Na⁺ and K⁺ selective absorption and transportation. Compared with S-SP, the leaf Na⁺/K⁺ ratio of S-IP decreased by 20.63%, the leaf salinity hazard coefficient (LSHC) decreased by 53.95%, so the photosynthetic potential and light energy conversion efficiency were significantly improved too. Ultimately the dry matter accumulation capacity and yield potential were improved, in which the yield potential under S-IP had the most obvious increase, and the yield under S-IP increased by 17.95% in 2019 compared with 2018.【Conclusion】The continuous peanut intercropped with sorghum under salt stress could be an effective technique to alleviate peanut negative interactions, which significantly improved STI and alleviate salt stress of peanut by improving soil nutrient status and regulating peanut Na⁺/K⁺ homeostasis, which ultimately maintained the dry matter accumulation capacity and increased yield potential.